1. Field of the Invention
The invention relates generally to operating system environments, and more particularly, to systems and methods for interpreting requests from foreign and native applications executing within a single native operating environment.
2. Description of the Related Art
Conventionally, the mechanisms by which a computer application requests operating system services are limited, and generally imposed by the underlying system hardware. More particularly, when an application requests an operating system service from an operating system, the application typically issues the request by invoking a special central processing unit (CPU)-specific “trigger instruction.” Upon receiving this trigger, the CPU will transfer control from the application to a specific location in the operating system. This location is identified by the operating system by writing the location's address to a special control register in the CPU. This register is typically written to once when the operating system is initially booted, and is never modified again. However, given the limited number of trigger mechanisms available in a processor, it is common for different operating systems to make use of the same triggers. Therefore, if a native operating system attempts to host a non-native application written for different operating system, the native operating system should expect the non-native application to request operating system services using the same mechanisms as those being used by a native application. Interpreting different types of operating system service requests via the same mechanism can impose an unnecessary performance penalty on native applications as well as non-native applications.
In view of the forgoing, there is a need to provide an efficient operating system interposition mechanism for delivering expected operating system services to non-native applications without affecting the performance of native applications.